(a)[3]
Define the term ecosystem.
(b(i))[3]
Suggest the assumptions that need to be made for the mark-release-recapture method to be valid.
(b(ii))[2]
In a first catch, $27$ golden poison dart frogs were trapped, marked and released. In a second catch, $33$ frogs were taken and $13$ of them carried marks. Apply the Lincoln index to estimate the frogs' population size. The population estimate is $\frac{n_1 \times n_2}{m_2}$, where $n_1$ is the number of individuals captured in the first sample, $n_2$ is the number of individuals (both marked and unmarked) captured in the second sample, and $m_2$ is the number of marked individuals recaptured in the second sample.